At the last "US Open" in Corpus Christi a year and a half ago, the Formula fleet raced in the mornings in winds up to 25 knots, the kites raced in the afternoon on the SAME course (upwind and downwind) in 25 knot + winds.
The top few kiters got around in roughly the same time as the formula boards, but what was interesting was the downwind run. While the formula sailors were holding on for dear life with 9.0 sails, the kites simply de-powered (kept them high) and ran dead downwind with ease, but slower than the formula boards. The 4' chop in the bay makes downwind runs challenging to say the least. A formula sailor can't sheet out on a fully powered downwind run to de-power, it's all or nothing. One could head off 90 degrees from the wind and luff the sail, but you won't get to the finish line on a beam reach.
A good kiter can choose full power or no power with the same rig. I guess a sailor can luff the sail completely and de-power too, but it's a much smoother transition for a kite. I have never sailed a kite, just my observations.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.